EP1649889A1 - Catheter particularly for insertion of pace-maker or ICD-electrodes into a patient's body - Google Patents

Abstract

The catheter has a catheter wall (2), which defines one of lumens (6, 6), and a reinforcement provided in an axial and peripheral direction (A, P) in the catheter wall. The reinforcement is provided for stabilization of the catheter in torsional and/or buckling strength. The reinforcement is designed as a profile unit (5), which is adjusted to desired mechanical properties of the catheter in the axial and peripheral direction.

Description

The invention relates to a catheter, in particular for introducing cardiac pacemaker or ICD (= implantable cardioverter defibrillator) electrodes into a patient's body having a catheter wall and a reinforcement therein.

Such catheters are known to comprise at least one lumen which is bounded by the catheter wall and serves to guide the electrode to be inserted after insertion of the catheter into the patient's body. The catheter can be pushed over a further lumen, for example, over a guide wire previously applied in the patient's body or equipped with a puller wire for the catheter tip.

Further, it is known that such catheters have a slit or tearable catheter wall along their longitudinal axial direction so that they can be easily removed therefrom upon placement of the electrode in the patient's body. Such a catheter is shown in EP 0 655 257 A2, which discloses a line of weakness in the form of a perforation in the catheter wall.

Finally, a common problem with such catheters resides in the torsional and kinking stability of the catheter shaft and its compression sensitivity, especially when the catheter has to be bent in a small radius, as is the case, for example, when inserted into the subclavian artery.

It is already known from the prior art to solve this problem, to provide reinforcements in the catheter wall, with the help of which the catheter is stabilized with respect to its torsional and / or bending stiffness and against undesired compression. EP 0 898 481 B1, US Pat. No. 6,159,198 and WO 99/33509 A1 disclose in this connection the insertion of reinforcing fibers into the catheter wall. These can be applied as individual fibers, as shown in WO 99/33509 A1 and EP 0 898 481 B1, or as a mesh tube, as is apparent from US Pat. No. 6,159,198.

Although the objective of reinforcement is basically achievable by the inserted fibers, such fiber inserts cause some problems, in particular with regard to catheter fabrication. Although the incorporation of fiber reinforcements in the form of a net or stranded structure in tubular structures is basically a common production method, however, such fiber reinforcements are difficult to adapt in the axial and peripheral directions to certain nominal properties. This is especially true for the weakening of the catheter to form a tear line. The mentioned EP 0 898 481 B1 shows in this connection a perforation line which only tears the reinforcing fibers running in the peripheral direction in the catheter wall in each case only. An implementation of this measure schematically illustrated in practice is likely to be possible only with considerable manufacturing effort. This applies all the more to the reinforcing fibers with a flat-rectangular cross-section which are likewise shown in the aforementioned publication, in which a severing of the reinforcing fibers is to be feared if the perforation lines are set too low.

Based on the described problems of the prior art, the present invention seeks to improve a catheter so that in a simple manner both in the axial and in the peripheral direction changing mechanical properties, such as torsion, bending, buckling stability, compressibility, flexibility and slitability can be generated.

The solution to this problem is specified in the characterizing part of claim 1 and provides in their basic expression, the gain form as a profile part, which is tuned in the axial and peripheral direction of the catheter on the mechanical properties of the shell. Thus, for example, by the changing wall thickness of the profile part over the length of the catheter changing flexibility, buckling resistance and compressive strength can be achieved. It is therefore advantageously no longer necessary - as is also known from the prior art - to set different different catheter shaft pieces together in the axial and / or peripheral direction of changing properties and to glue or weld them together. A slittability of the catheter can, for. B. be made by a made on the peripheral direction Wanddickeneinschnürung the profile part.

Fig. 1

eine höchst schematische, ausschnittsweise und teilweise weggebrochene Perspektivdarstellung eines Katheters in einer ersten Ausführungsform,

Fig. 2 bis 4

Perspektivdarstellungen analog Fig. 1 dreier weiterer Ausführungsformen des Katheters,

Fig. 5

eine schematische ausschnittsweise Perspektivdarstellung eines in den Katheter gemäß Fig. 4 eingesetzten Profilteils.

Preferred embodiments of the invention are specified in the subclaims. Other features, details and advantages of the invention will become apparent from the following description, are explained in more detail in the embodiments with reference to the accompanying drawings. Show it:

Fig. 1

a highly schematic, partial and partially broken away perspective view of a catheter in a first embodiment,

Fig. 2 to 4

Perspective representations analogous to FIG. 1 of three further embodiments of the catheter,

Fig. 5

a schematic partial perspective view of a profile member used in the catheter of FIG. 4.

The catheter 1 shown in Fig. 1 has a catheter wall 2, which is constructed radially from the inside to the outside by an inner tube 3, an outer tube 4 and a profile part 5 lying therebetween. In the inner tube 3, two extending from the proximal to the distal end (each not shown) of the catheter 1 lumen 6, 6 'are applied, through which, for example, a pacemaker electrode and a pull wire are pushed through. Inner and outer tube 3, 4 are made of an extruded elastomeric material, as is common for use in medical tubing and tubes.

In the exemplary embodiment shown in FIG. 1, the profile part 5 is designed as a longitudinally cylindrical lattice profile part, which in the illustrated region is divided into partial lengths t1, t2, t3, t4 and t5 with different profiling. In principle, axial webs 8 extending in the axial direction A through apertures 7 and peripheral webs 9 extending in the peripheral direction P are formed. As indicated in the drawing, by a variation of the thickness of the shell wall of the grating profile part 5, and in particular the size of the openings 7 and / or the cross-sectional dimensioning of the axial and peripheral webs 8, 9, the profile part in different partial lengths t1 to t5 be designed so that it is tailored to the mechanical properties of the catheter. For example, by increasing the size of the openings 7 toward the distal end, with a corresponding reduction in the widths of the axial and peripheral webs 8, 9, the torsional and bending resistance of the catheter 1 over the partial length t1 can be significantly reduced compared to the partial length t2. Furthermore, as not explicitly shown, only very thin and short peripheral webs 9 can be left standing between two rows of openings 7, whereby these then form a predetermined breaking point for severing the catheter 1 and removing it from the inserted electrode. Also, a "mixed form" of axial and peripheral webs can be realized by oblique diagonal webs.

On the part length t3, the profile part is not provided with openings 7, that is cylindrical, whereby it is very stable to compression.

This is followed on the part length t4 a range of elongated openings 7, which form parallel to each other axial webs 8 between them. In this area, the profile part 5 is relatively torsionally unstable, so it can be easily twisted in itself.

Finally, on the part length t5, a relatively narrow grid pattern of axial and peripheral webs 8, 9 is applied through narrowed openings 7, which makes the profile part 5 very flexible in this part, albeit torsionally stable.

The grating profile part 5 according to FIG. 1 can be produced in various ways. Thus, a laser cutting, punching or etching of a tube, tube or flat material, such as a piece of film is possible. In the latter case, the profiled in the flat state piece of material is then rolled and wound as a profile part, for example on the inner tube 3. A production as injection-molded, extruded or similarly hot-formed tube or tube is conceivable.

The above semifinished products may be made of plastic material such as polycarbonate, polyimide and the like or of a metal material such as nitinol or stainless steel.

The grid profile part 5 thus produced as a semi-finished product can be embedded between the inner and outer tubes 3, 4 after its production by gluing, shrinking or melting. A direct injection into a one-piece hose wall is possible.

In addition to the above mechanical and thermoplastic production techniques, the grating profile part 5 can also be produced by coating the inner tube 3 with a UV or laser light or chemically hardenable plastic by a kind of lithographic process. For this purpose, a mask is placed on the coating, which is a negative of the desired grid profile. By irradiation or contact with a chemical hardener - such as by dipping or spraying - the coating is cured at the exposed, vacant from the mask by crosslinking and then removed the mask. Then the uncured zones of the coating can be washed out with a suitable solvent and the grid profile part 5 with the desired pattern of holes remains. The outer tube 4 is then shrunk over the profile part 5 thus produced with inner tube 3, glued or extruded.

The above masking can be omitted if the coating is scanned with a scanner laser or focused UV light in the zones to be cured and crosslinked there.

Finally, the profile part 1 can also be produced by printing the inner tube 3 with a "web image" of a curable material such as a corresponding printing paste, and then curing the material by radiation or chemical crosslinking.

In the embodiment of the catheter 1 'shown in FIG. 2, in turn, an inner tube 3 having two lumens 6, 6', an outer tube 4 and a profile part 5 'located therebetween are provided. The latter is provided with a deviating from the embodiment of FIG. 1 profiling on its partial lengths t1 to t4. Characteristic in this embodiment is the design of the profile part 5 'to the effect that the catheter 1' defined on these partial lengths t1 to t4 is particularly well bendable in certain planes. Thus, on the part length t1 on two opposite sides juxtaposed, gore-shaped openings 7 are provided which form between them peripheral webs 9 with hourglass-shaped width profile. The peripheral webs 9 are interconnected by two opposite axial webs 8. By this configuration, the catheter on the part length t1 is particularly good in the plane of FIG. 2 bendable.

On the part length t2, the gore-shaped openings 7 are offset by 90 ° relative to those on the partial length t1 and arranged at a greater distance from one another. As a result, the catheter is stiff on this partial length t2 in the plane of the drawing in FIG. 2, but is easily bendable for a deflection movement out of the plane of the drawing. Due to the larger distance the openings 7 with respect to part length t1 but the overall flexibility is lower.

On the part length t3 successive openings 7 are each offset by 90 ° to each other, so that a kind of inclined grille profile part with oblique peripheral webs 9 and axially interrupted axial webs 8 is formed. Due to the 90 ° offset of successive openings 7, the catheter 1 'on this part length t3 is flexible both in the plane of the drawing of FIG. 2 and perpendicular thereto.

On the part length t4 a few openings 7 are still provided at a great distance from each other, so that in the local area of the catheter 1 'is very stiff and possibly low bendability in the plane of the drawing of FIG. 2 (analog partial length t1) shows.

With regard to the production and integration of the profile part 5 'in the catheter assembly can be made to the comments on Fig. 1.

In the embodiment of the catheter 1 "shown in FIG. 3, the lattice structure of the profile part 5" is applied directly in the inner tube 3. In the case shown, the latter again has two lumens 6, 6 'and is provided on its surface with a hatched highlighted in Fig. 2, a total of a grid structure with axial and peripheral webs 8, 9 forming reinforcement. For this purpose, a curable material is used for the inner tube 3, which is irradiated in the hatched in Fig. 3 zones and thereby cured. A removal of the non-irradiated zones can be omitted, so that despite the integrated reinforcement, the component has a flat surface. To further harden the inner tube 3, and thus to prevent further reinforcement by growing the webs 8, 9 of the profile part 5 ", in turn, an outer tube 4 is applied in the manner discussed.

Another embodiment of a catheter 1 '' 'is finally shown in Figs. 4 and 5. In the inner and outer tubes 3, 4, this embodiment does not differ from that shown in FIG. 1. In this regard, reference is made to the statements there.

The profile part 5 '' 'is made in one piece from a hard plastic material, such as polycarbonate or polyimide, or from thin metal material, such as stainless steel or Nitinol, and has on the partial lengths t1, t2 and t4 parallel spaced apart peripheral webs on. These are designed as partial rings whose ends 11 are each connected to each other by an axially continuous axial web 8, 8 '. Between the two axial webs 8, 8 'remains a gap 12, which serves in the catheter 1' '' as a predetermined breaking point for its separation for removal from the inserted electrode.

Also in the embodiment shown in Fig. 4, the openings 7 and in particular peripheral webs 9 are designed differently on the different partial lengths t1 to t4. In the partial length t1 arranged towards the distal end, relatively thin peripheral webs 9 are provided, so that the catheter is relatively flexible there. In the partial length t2 adjoining in the proximal direction, the peripheral webs 9 are significantly widened, as a result of which the flexibility decreases.

A special feature of the axial webs 8, 8 'in the region of the partial length t3. There, the axial webs 8, 8 'in the peripheral direction P facing extensions 13, 13 'which are offset relative to one another in such a way that they mesh with one another to form a meander-shaped gap section 12'. In this area, the catheter 1 '"is thus torsionally stable.

On the part length t4 relatively thin peripheral webs 9 are separated from each other by axially wide openings 7, so that the catheter is there very flexible in the plane passing through the gap 12 center plane.

This is followed by a partial length t5, in which no openings except gap 12 are provided. As a result, there is the catheter 1 '' 'very stiff.

In Fig. 5, the profile part 5 '' 'is shown on its part length t1 without inner and outer tube.

Finally, it should be noted that the profile parts can be made of a material that is compatible for MR viewing devices or detectable in ultrasound or X-ray devices.

Claims (10)

Catheter, in particular for introducing pacemaker or ICD electrodes into a patient's body a catheter wall (2) delimiting at least one lumen (6, 6 '), and a reinforcement in the axial and peripheral direction (A, P) in the catheter wall (2) for stabilizing the catheter (1, 1 ', 1'',1''') with respect to its torsional and / or bending stiffness, characterized in that - The gain as a profile part (5, 5 ', 5 ", 5''') is formed in the axial and peripheral directions (A, P) of the catheter (1, 1 ', 1", 1''') on whose mechanical properties are matched. Catheter according to claim 1, characterized in that the profile part (5, 5 ', 5 ", 5''') at different part lengths (t1 to t5) by means of variable profiling tuned torsion, bending buckling stiffness, Schlitzbarkeits- and / or Compressibility features. Catheter according to claim 1 or 2, characterized in that the profile part at least on a partial length (t1 to t5) as a grating profile part (5, 5 ', 5''') with axial and / or peripheral webs (8, 9) is formed. Catheter according to claim 3, characterized in that the cross-section of the axial and / or peripheral webs (8, 9) in the axial and / or peripheral direction (A, P) with respect to the torsional, bending, buckling stiffness, slitability and / or or compressibility properties of the catheter (1, 1 ', 1''') is variable. Catheter according to claim 3 or 4, characterized in that the grating profile part (5 "') has part-annular peripheral webs (9) which are connected at their ends by an axially continuous axial web (8, 8'). Catheter according to one of the preceding claims, characterized in that the profile part (5, 5 ''') is made by cutting or etching of a tube or foil part made of metal or plastic material. Catheter according to one of claims 1 to 6, characterized in that the webs (8, 9) of the profile part (5 ") are produced by radiation-induced or chemical crosslinking of a curable plastic tube part or a curable coating. Catheter according to one of claims 1 to 6, characterized in that the profile part (5, 5 ', 5''') is produced by a hot-forming process, in particular by injection molding, extrusion or the like. Catheter according to one of the preceding claims, characterized in that the profile part (5, 5 ', 5'',5''') embedded in the catheter wall (2), in particular injected. Catheter according to one of claims 1 to 8, characterized in that the profile part (5, 5 '', 5 ''') between an inner tube (3) and an outer tube (4) of the catheter wall (2) is embedded.

Images